Patchwork block2mtd: throttle writes by calling balance_dirty_pages_ratelimited.

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Submitter Neil Brown
Date Dec. 12, 2012, 8:32 a.m.
Message ID <20121212193215.645da577@notabene.brown>
Download mbox | patch
Permalink /patch/205455/
State Accepted
Commit 031da73fca29ebba3eea5a512746e01d52e542cd
Headers show

Comments

Neil Brown - Dec. 12, 2012, 8:32 a.m.
If you create a block2mtd device that is larger than main memory,
and write to all of it, then lots of pages will be dirtied but
they will never be flushed out as nothing calls any variant of
balance_dirty_pages.

It would be nice to call set_page_dirty_balance(), but that isn't exported,
so just call balance_dirty_pages_ratelimited() directly.

Signed-off-by: NeilBrown <neilb@suse.de>
Artem Bityutskiy - Dec. 13, 2012, 11:29 a.m.
On Wed, 2012-12-12 at 19:32 +1100, NeilBrown wrote:
> 
> If you create a block2mtd device that is larger than main memory,
> and write to all of it, then lots of pages will be dirtied but
> they will never be flushed out as nothing calls any variant of
> balance_dirty_pages.
> 
> It would be nice to call set_page_dirty_balance(), but that isn't exported,
> so just call balance_dirty_pages_ratelimited() directly.
> 
> Signed-off-by: NeilBrown <neilb@suse.de>

Pushed to l2-mtd.git, thanks!

Patch

diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index 681e2ee..2c3e8e7 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -62,6 +62,7 @@  static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
 				memset(page_address(page), 0xff, PAGE_SIZE);
 				set_page_dirty(page);
 				unlock_page(page);
+				balance_dirty_pages_ratelimited(mapping);
 				break;
 			}
 
@@ -152,6 +153,7 @@  static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
 			memcpy(page_address(page) + offset, buf, cpylen);
 			set_page_dirty(page);
 			unlock_page(page);
+			balance_dirty_pages_ratelimited(mapping);
 		}
 		page_cache_release(page);